Cloud Config Server should be able bootstrap resources

Is your feature request related to a problem? Please describe.
When the spring.cloud.config.server.bootstrap property is set to true, the config-server should configure itself like it was any other config-client, which it does well, as long as you don't need a resource, like a logback-spring.xml during bootstraping.
This is not a problem for clients, because I can just use a config like this: logging.config=${spring.cloud.config.uri:http://localhost:8888/}/${spring.application.name}/${spring.profiles.active:default}/master/logback-spring.xml and the client will send another request to the config server asking for this resource.

The problem is that during config-server bootstraping, this endpoint is not yet available.

Describe the solution you'd like
I don't know if there are other usecases (not logging reinitialization related) where this issue arises. If there aren't (which I suspect is the case) than the solution is simply to try and request the resource bypassing the endpoint, for example by invoking this.repository.findOne(name, profiles, label, includeOrigin); directly.

code taken from org.springframework.cloud.config.server.environment.EnvironmentController:136

If there are other usecases, we might need a more sophisticated solution.

Describe alternatives you've considered
I have considered some hacky solutions by defining root search locations, but these are shady and situational.

Start at org.springframework.cloud.config.server.environment.EnvironmentController around line 136 and inspect the bootstrap path controlled by spring.cloud.config.server.bootstrap. Compare it with repository.findOne(name, profiles, label, includeOrigin); done means bootstrap can obtain the needed resource without relying on the unavailable endpoint, with tests covering the behavior.